I have a very similar situation to this. Last fall I ran out of Baquacil and was having trouble with water mold. Thought about converting to chlorine this year to give it a try. Last fall I was not trying to do the conversion but maybe I have already. I can’t remember exactly how much chlorine I put in. So if the baquacil level was low and I put in approx 10 - 15 gal (guessing) of the 12% over the course of a few days, have I maybe pretty much converted it already? It went through some interesting color changes and in the end was crystal clear. No testing was done other than some test strips I had laying around. They showed a high level of chlorine but it was gone by the next day and that is when I added more. Kept it up until it was nice and clear. I dumped my sand this fall. I actually have it in a trash can. Am I ok to just use my new sand or do I run the risk of gumming it up still. I’m thinking it is a hard thing to answer as I was not really testing and all that good stuff. I could put some of the old sand back in, maybe 1/3 full just to be safe, shock the pool, and then replace it after a week or two. We all know how much of a pain changing sand can be so what do you think? If I had the pool looking clear, can that be a good indicator of a complete conversion and to just go ahead and put the new sand in for this year?